Tungsten heavy alloy sheet can be produced by rolling sintered slabs of the alloy. Because the rolling requires numerous anneals it is desirable that the starting slab be no more than about twice the final thickness. One method to produce these slabs is by isostatically pressing the powder alloy blends and sintering them to full density. With thin slabs it is difficult to get a uniform fill of the mold so the resulting slabs are not uniform in thickness. There is also a problem with breakage with the thin slabs. Using this method it is not possible to produce slabs with a surface area to thickness ratio much over 600 or thickness less than about 0.5".
Another method of making tungsten heavy alloy sheet is to press large billets and cut the green billet into thin slabs. While this process produces slabs of uniform thickness it has the size limitations of the previous method and there is the added expense of cutting.
It would be desirable to make a sheet preform substantially close in thickness to the final thickness of the rolled sheet. This would reduce the time, energy, and labor required for hot rolling and annealing.
U.S. Pat. No. 2,735,757 relates to a process for forming iron metal powder from iron salts by oxidizing a solution of the iron salts to produce a hydrate sludge of the iron, followed by reducing the iron to the metal powder.
U.S. Pat. No. 3,663,667 discloses a process for producing multimetal alloy powders wherein an aqueous solution of at least two thermally reducible metallic compounds and water is formed, the solution is atomized into droplets having a droplet size below about 150 microns in a chamber that contains a heated gas whereby discrete solid particles are formed and the particles are thereafter heated in a reducing atmosphere and at temperatures from those sufficient to reduce the metallic compounds to temperatures below the melting point of any of the metals in the alloy.
U.S. Pat. No. 4,348,224 relates to a process for producing fine cobalt metal powders by digesting cobalt bearing scrap in hydrochloric acid to produce an aqueous cobalt acid chloride solution containing copper and silver ions which are removed by cementation with iron to result in a cobalt chloride solution which is processed to fine cobalt metal powder.
U.S. Pat. Nos. 3,663,667 and 4,348,224 are assigned to the same assignee as the present invention.